Rotary switch with movable double bladed contacts



Oct. 19, 1965 w. A. SEFTON 3,213,212

ROTARY SWITCH WITH MOVABLE DOUBLE BLADED CONTACTS Filed July 11, 1962 I as 6 28 I2 2 Sheets-Sheet l INVENTOR. WlLLlAM A. E TON W ATTORNEY Oct. 19, 1965 w. A. SEFTON 3,213,212

ROTARY SWITCH WITH MOVABLE DOUBLE BLADED CONTACTS Filed July 11, 1962 2 Sheets-Sheet 2 INVENTOR.

Wu. IAM A. SEFTON 142 fl//7/ ATTORNEY United States Patent 3,213,212 ROTARY SWITCH WTTH MOVABLE DOUBLE BLADED CONTACTS William A. Sefton, Grafton, Wis., assignor to Globe- Union Inc., Milwaukee, Wis., a corporation of Delaware Filed July 11, 1962, Ser. No. 209,062 13 Claims. (Cl. ZOO-14) This invention relates to an improved rotary switch and particularly to a switch which is used for testing vacuum tubes.

The increasing complexity of vacuum tubes has, in turn, complicated the equipment necessary for testing such tubes. Attempts to provide multiple switching arrangements from conventional parts has resulted in an increase in the overall size of the switch. If the switches are made from smaller parts in order to meet size requirements, the electrical load capacity of the switch is not suflicient to carry the electrical load in the circuits of the tube.

The primary object of this invention is to provide a switch of reduced size and increased switching functions and to maintain the electrical load capacity of the switch.

A further object of this invention is to provide an improved rotor and contactor assembly that can be quickly and accurately assembled with a minimum of skill.

In order to accomplish these objects a rotor is journaled between two stators with double bladed contacts secured to the rotor in a position to engage both stators. Each stator has an equal number of terminals mounted thereon in an opposed aligned relation and an independent contact member mounted on one of the stators to provide the read-out or test circuit. The number of double bladed contacts on the rotor is equal to the number of pairs of terminals on the stators so that all except one of the pairs of terminals will be interconnected by the contacts in each position of the rotor. The one pair of terminals which is not interconnected is short circu'ited to the read-out contact member. One pair of terminals can then be checked in each position of the switch. The double bladed contacts are provided with a tab which is nested into a groove in the rotor during assembly to properly align the contacts in the rotor.

Other objects and advantages will be pointed out in or be apparent from the specification and claims, as will obvious modifications of the embodiment shown in the drawings, in which:

FIG. 1 is a view in side elevation of the switch;

FIG. 2 is a view taken on line 2-2 of FIG. 1 showing the indexing mechanism;

FIG. 3 is a view taken on line 3-3 of FIG. 1 showing the common contact terminal on the face of the stator;

FIG. 4 is a view taken on line 4-4 of FIG. 1 showing the face of the opposite stator;

FIG. 5 is an end view of the rotor;

FIG. 6 is a view of the other end of the rotor; and

FIG. 7 is a view of the strut mounting arrangement.

Referring more particularly to the drawings, switch assembly 10 is mounted on a switch panel 12 (shown partly broken away in FIG. 1) by inserting shaft 14 and bushing 16 through aperture 18. Nut 20 and washer 22 are used to secure the bushing on the panel. A knob (not shown) is provided on the end of the shaft to rotate the switch to the desired positions and a snap ring 17 holds the shaft in the bushing.

An indexing mechanism 24 is provided on the switch assembly to positively locate the shaft in each of the positions provided on the switch. The index mechanism includes a front plate 26 and spring 28 rigidly secured to the bushing and an index wheel 30 rigidly secured to the shaft. A ball 32 is mounted in aperture 34 in the front plate and is biased by the spring into engagement with the index wheel. On rotation of the shaft, the ball will seat in one of the dwells 35 in the index locating the shaft at a particular position.

The shaft extends through stators 36 and 38 which are secured to the front plate by bolts 40. Spacers 42 and 44 are provided between the front plate and stator 36 and stator 38, respectively. Nut 46 and lock washer 48 are provided on the end of the bolts to secure the assembly together.

Rotor 50 is journaled between the stators and is mounted to rotate with the shaft. A number of contactors 52 having equal length arms 54 are mounted on the rotor by eyelets 56. The outer ends 58 of the arms are biased to slide on the inner surfaces of the stators. A number of terminals 60 and 62 are mounted on and are equally spaced about the periphery of the stators and have contact surfaces 64 and 65 which are located in the circle of revolution of the ends of the contact arms on the rotor. The contact arms on the rotor are spaced the same as the terminals on the stators so that an electrical circuit will be completed between the terminals on one stator and the terminals on the other stator.

One of the contactors on the rotor is replaced by a read-out contactor 66 which has a normal length arm 68 and a short arm 70 that rides upon a full ring contact 72 on the stator 38. The full ring contact is connected to a checking circuit to thereby check the tube circuit connected to the terminal engaged by contact arm 68.

The rotor is made of molded plastic and is so designed that the contactors are individually nested in the rotor. The contact arms are made of a single piece of material which is folded over to form the arms thereby insuring electrical continuity. The folded over section of the contactor has a tab 74 which pockets into a nest or groove 76 in the rotor to insure proper positioning and tightness of the contactors. The diameters of ends 61 of the rotor are accurately turned so that the rotor rides in holes 63 and 71 in the stator. End play is limited by shoulders 67 and 69 on the rotor.

The present switch is designed to check up to a fourteen terminal tube. Fourteen posit-ions are provided on the index wheel with a pair of terminals 60 and 62 provided on the stators at each position. Thirteen of these pairs of terminals are electrically connected by the contactors on the rotor in each position of the index wheel. The fourteenth pair is short circuited by the read-out contactor and connected to the full ring contactor. The read-out contactor will sequentially check the terminals in either direction of rotation.

In assembling the stator it is essential that the spacing between the stators be accurately predetermined to insure contact between the terminals and contactors. Space-rs 44 between the stators are therefore very accurately machined to provide the proper spacing. This arrangement provides a compact switch arrangement which has sufficient current carrying capacity to check tubes of this size.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A rotary switch mechanism comprising, in combination,

first and second stators,

a plurality of spaced electrical terminal means arranged in a circle on each of said stators,

read-out terminal means supported on said first stator,

rotor means,

means supporting said rotor means for rotation relative to said stators,

a plurality of electrical contactor means connected to and movable with said rotor means, each of said electrical contactor means arranged to extend between and electrically connect the terminal means on said stators in pairs so that circuits are completed between the terminal means on said stators in pairs,

and read-out contactor means connected to and rotatable with said rotor means, said read-out contactor means arranged for continuous engagement with said read-out terminal means and also arranged to sequentially engage the terminal means on said second stator so that the terminal means on said second stator are selectively connectable with said read-out terminal means.

2. The rotary switch mechanism of claim 1 including indexing means connected with said rotor means and operative to index movement of said rotor means to positively locate said electrical contactor means and said read-out contactor means relative to and for engagement with said stator terminal means.

3. The rotary switch mechanism of claim 2 wherein said indexing means comprises,

an index wheel connected to and rotatable with said rotor means, said index wheel including a plurality of relatively spaced, peripherally arranged, radial dwells,

a ball,

means supporting said ball in fixed relation relative to to said index wheel and in the path of rotation of said dwells,

and means engaging said ball and operative to exert a biasing force on said ball in radial direction relative to said index wheel so that said ball is biased into selective engagement with said dwells to index said rotor means.

4. The switch mechanism of claim 1 wherein said stators each include an aperture with said apertures coaxially arranged relative to each other and wherein said rotor mens includes first and second relatively spaced bearing surfaces, one of said bearing surfaces journaled in one of said apertures and the other journaled in the other aperture.

5. The switch mechanism of claim 1 wherein said electrical contactor means each comprises a generally U- shaped continuous strip of resilient electrically conductive material the closed end of which is connected to said rotor means and the free ends of which are arranged to selectively engage the terminal means on said stators.

16. The switch mechanism of claim 5 wherein said readout contactor means comprises a generally U-shaped continuous strip of resilient electrically conductive material the closed end of which is connected to said rotor means and one free end of which is arranged for continuous engagement with said read-out terminal means and the other free end of which is arranged to sequentially engage the terminal means on said second stator.

7. A rotary switch comprising, in combination,

first and second stators.

means supporting said stators in spaced parallel relationship,

a plurality of relatively spaced electrical terminal means arranged in a circle on each of said stators and the terminal means on said first stator coaxially arranged with the terminal means on said second stator,

rotor means,

means supporting said rotor means for rotation relative to and coaxially with said first and second stators,

an annular terminal on said first stator coaxially ar- 4, ranged with but offset from said terminal means on said stators,

a plurality of generally U-shaped electrical contactor means connected at their closed ends to said rotor means for rotation therewith and having their free ends extending to the circles of and engaging said stator terminal means, each of said electrical contactor means extending between and electrically connecting terminal means on said first stator to terminal means on said second stator so that circuits are completed between the terminal means of said stators in pairs,

and generally U-shaped read-out contactor means connected at its closed end to said rotor means for rotation therewith and having one of its free ends extending to and continuously engaging said annular terminal and its other free end extending to the circle of the terminal means on said second stator for sequential engagement therewith.

8. In a rotary switch having a pair of stator members positoned in a parallel relation with a number of terminals equally spaced in a circle about the axis of the stator and aligned on the oppositely positioned faces of the stators and an annular terminal mounted on the face of one of the stators, a rotor comprising,

a generally cylindrical member having bearing surfaces as its ends,

a radially extending groove in the rotor for each pair of terminals on the stators,

said grooves being equally spaced about the axis of the rotor,

a number of contactors each in the form of a single strip of electrically conductive material and folded back on itself to form a closed end and a pair of equal length contact arms,

the closed end portion of said contactors being positioned in said grooves and secured to the rotor with the arms of the contactors positioned to rotate in the circle of revolution of the terminals on the stators and to interconnect the terminals on the opposed faces of the stator,

and a contactor also in the form of a single strip of electrically conductive material and folded back on itself to form a closed end and a pair of contact arms, said last-mentioned contactor positioned with its closed end in one of said grooves, one contact arm positioned to engage the terminals on the other stator member and the other arm thereof positioned to engage the annular terminal to short circuit one of the pairs of terminals on the stators.

9. A fourteen position tube checker switch comprising,

a pair of stators having fourteen equally angularly spaced terminals on one face of each stator,

means for supporting said stators in a parallel relation with the terminals facing each other in an aligned relation,

one of said stators having a continuous annular termi nal mounted on said one face of one of the stators,

a rotor journaled in the stators in the space between the stators,

thirteen electrical contactors each in the form of a single strip of material and folded back on itself to form a closed end and a pair of contact arms,

means for mounting said contactors in the rotor in an angular relation corresponding to the angular relation of the terminals,

and a single contactor mounted in said rotor and having one contact arm to engage the terminals on one stator and another contact arm to engage the annular terminal on the other stator terminal whereby thirteen pairs of the terminals on the stators are interconnected in each position of the rotor and one pair of terminals is short circuited to the annular terminal in each position of the rotor.

10. A switch according to claim 9 wherein said means for supporting said stators includes spacers for spacing said stators a predetermined distance apart.

11. A switch according to claim 9 wherein means for mounting said contactors in the rotor comprises, a number of grooves corresponding to the number of terminals on one of said stators, said grooves being equally angularly spaced about the axis of the rotor, and an aligning tab on each of said contactors which nests in the groove when the contactors are secured thereto.

12. A switch mechanism comprising, in combination,

first and second sets of electrical terminal means,

read-out terminal means,

first means for supporting said first and second sets of terminal means and said read-out terminal means in relative spaced relation,

a plurality of electrical contactors,

a read-out contactor,

second means for supporting said electrical contactors and said read-out contactor in relative spaced relation corresponding to the relative spacing between said electrical terminal means and said read-out terminal means with each of said electrical contactors extending between and electrically connecting a terminal means of said first set to a terminal means of said second set and with said read-out contactor arranged for continuous engagement with said readout terminal means and for sequential engagement 'with the terminal means of one of said first and second sets,

and means for connecting said first and second support means for relative movement therebctween to sequentially electrically connect the terminal means of said first and second sets in pairs and sequentially electrically connect the terminal means of said one of said sets to said read-out terminal means.

13. A rotary switch comprising, in combination,

first and second stators,

means supporting said stators in spaced parallel relationship,

a plurality of equally angularly spaced terminal means arranged in a circle on said first stator and an equal number of equally angularly spaced terminal means on said second stator aligned with the terminal means on said first stator,

a generally angular terminal supported on said first stator in coaxial relationship with said stator terminal means,

a plurality of electrical contactors equal in number to the number of terminal means on one of said stators, all but one of said electrical contactors engaged between aligned pairs of terminal means on said first and second stators, and said one electrical contactor engaged between a terminal means on said second stator and said generally annular terminal,

and means supporting said electrical contactors for rotation relative to and coaxially with said stator so that the terminal means on said second stator are selectively connectable with said annular terminal with the remainder of the stator terminal means being electrically connected in pairs.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES German application, Ser. No. S, 39905 V111c/21g,

Dec. 27, 1955.

German application, Ser. No. F, 16600 11/63-c, Dec.

BERNARD A. GILHEANY, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Non 3 ,213, 212 October 19, 1965 William A. Sefton It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 45, for "mens" read means column 6, line 6, for "angular" read annular Signed and sealed this 14th day of June 1966 (SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNEI Commissioner of Patents 

1. A ROTARY SWITCH MECHANISM COMPRISING, IN COMBINATION, FIRST AND SECOND STATORS, A PLURALITY OF SPACED ELECTRICAL TERMINATL MEANS ARRANGED IN A CIRCLE ON EACH OF SAID STATORS, "READ-OUT" TERMINAL MEANS SUPPORTED ON SAID FIRST STATOR, ROTOR MEANS, MEANS SUPPORTING SAID ROTOR MEANS FOR ROTATION RELATIVE TO SAID STATORS, A PLURALITY OF ELECTRICAL CONTACTOR MEANS CONNECTED TO AND MOVABLE WITH SAID ROTOR MEANS, EACH OF SAID ELECTRICAL CONTACTOR MEANS ARRANGED TO EXTEND BETWEEN AND ELECTRICALLY CONNECT THE TERMINAL MEANS ON SAID STATORS IN PAIRS SO THAT CIRCUITS ARE COMPLETED BETWEEN THE TERMINAL MEANS ON SAID STATORS IN PAIRS, AND "READ-OUT" CONTACTOR MEANS CONNECTED TO AND ROTATABLE WITH SAID ROTOR MEANS, SAID "READ-OUT" CONTACTOR MEANS ARRANGED FOR CONTINUOUS ENGAGEMENT WITH SAID "READ-OUT" TERMINAL MEANS AND ALSO ARRANGED TO SEQUENTIALLY ENGAGE THE TERMINAL MEANS ON SAID SECOND STATOR SO THAT THE TERMINAL MEANS ON SAID SECOND STATOR ARE SELECTIVELY CONNECTABLE WITH SAID "READ-OUT" TERMINAL MEANS. 